Chromatographic switching valves



Sept. 5, E L. KARAS CHROMATOGRAPHIC' SWITCHING VALVES Filed July 25,1965 2 Sheets-Sheet 2 INVENTOR. EDWIN L. KARAS DOM 2% ATTORNEY "of theinvention; and

United States Patent 3,339,582 CHROMATOGRAPHIC SWITCHING VALVES Edwin L.Karas, Sharon, Mass., assignor to The Foxboro Company, Foxboro, Mass., acorporation of Massachusetts Filed July 23, 1965, Ser. No. 474,354

Claims. (Cl. 137624.13)

ABSTRACT OF THE DISCLOSURE A chromatographic switching valve employs arotatable cylinder with a compression spring therein each end of whichurges respective combinations including a resilient body and rotatablemember against abutting faces of respective stationary members so thatchannels in each rotatable member selectively bridge passages in saidrespective stationary members.

This invention relates to valves and, more particularly, to actuatedvalves suitable for switching chromatographic columns.

The present invention provides means for chromatographic columnswitching having necessary characteristics of precision, durability, aswell as being failsafe. The illustrated embodiment employs a group offour switched passages; alternate adjacent passages are inter-connectedin turn by rotary switching means. The invention may be adapted toswitch fewer or more passages by employing the means thereof.

It is an object of this invention to provide a rotary chromatographicswitch having a simple actuating means capable of long-term operationwithout losing count or nus-switching.

It is another object of this invention to provide a rotary switchactuated directly by electrical and mechanical means.

:1 "It is another object of this invention to provide a rotary switchingmeans having provision for wear compensation jdis mantled for inspectionor repair, without tools and 1 without uncoupling tube connections.

It is another object of this invention to provide a chromatographicswitching valve having minimum side -capacity for fluids.

It another object of this invention to provide a chromatographicswitching valve which may alternatively .be utilized as a vapor samplingvalve.

It is another object of this invention to provide explosion-proofchromatographic switching means capable vof operation in all types ofenvironments.

These and other features of the invention will become apparent-from thefollowing detailed description thereof,

ftak'en 'in conjunction with the several figures in the drawing, inwhich:

FIGURE 1 is a cross-sectionalview of an embodiment FIGURE 2 is a view ofthe invention at right angles to the plan of FIGURE 1, showing some ofthe operating elements in an exposed depiction thereof.

Referring now to FIGURE 1, valve body 10 is fitted at opposing partsthereof with bearings 11 and 12 having Patented Sept. 5, 1967 balls 15and 16, thereby exerting force on said balls 15 and 16, tending toincrease the spacing between them. Metal balls 15 and 16, in turn, arecentered in washers 17 and 18 disposed at right angles to the axis ofcylinder 13, thereby causing pressure to be exerted through washers 17and 18, against rubber discs 19 and 20, adjacent thereto. Rubber discs19 and 20 tend to exert an equalized pressure over the contactingsurfaces thereto of Teflon glands 21 and 22.

Teflon glands 21 and 22 are locked in the direction of rotation of valvecylinder 13 by means of locking alignment clips 9, the latter shown inFIGURE 2. In this manner, the combination stack of compression spring14, balls 15 and 16, washers 17 and 18, rubber discs 19 and 20, andTeflon glands 21 and 22 are actually axially disposed within theinterior of valve cylinder 13, rotating in alignment with the body ofvalve cylinder 13. Thereby, rotation of the glands 21 and 22 producesrelative movement of passages 21a and 21b in gland 21 and passages 22aand 22b in gland 22.

Valve seat 23 is compressed against the outwardly disposed surface ofgland 22 by means of screw cap 24,

coupling onto threads of valve body 10. Valve seat 23 contains fourports, 23A, B, C, D, brought therethrough to its face compressed againstgland 22. These ports 23A, B, C, D connect to passages 25A, C, D, whichexit from valve seat 23 through a center hole 24A, provided for exitmeans in the center of screw cap 24. Valve seat 23 is aligned with valvebody 10' by means of locating pin 26, in order to obtain the desiredcorrespondence between ports 23 and passages 22A and 223 in gland 22.

Referring to FIGURE 2, valve cylinder 13 has four index pins, 27A, B, C,D, axially aligned and alfixed to its exterior, providing means for lip28A of plunger hook 28 to catch, where-by plunger hook 28 is enabled tocause valve cylinder 13 to turn with the movement of hook 28. Plungerhook 28 is flexibly fastened to solenoid 29 by screw 30. Washer 31 andpositioning spring 32 operate to tend to position plunger hook 28parallel to the direc- 50 tion of solenoid 29 movement. By this means,each stroke of solenoid 29 pulls hook 28 flexibly attached thereto andpin 27A of valve cylinder 13 taut in lip 28A of hook 28, thus turningvalve-cylinder 13 a, quarter turn. As noted, valve glands 21 and 22 turnin synchronism with the body of valve cylinder 13. Upon magnetic releaseof solenoid 29, the return spring 33 pushes solenoid 29 back toward itsnon-actuated position and hook 28 is permitted by its flexibleconnecting washer 31, and positioning spring 32 to flex over the body ofvalve cylinder 13, riding away from pin 27A to apoint where hook 28 hasits lip 28A reach past the next pin 27B in sequence, catching pin27B bythe constraining action of positioning spring 32. The next successiveactuation of solenoid 29 then causes valve cylinder 13 to rotate anotherone-quarter turn, repeating the sequence of plunger actuation andrelease.

Gland 22 contains passages 22A and B, having dimensions calculated tobridge the distance between two adjacent ports in Valve seat 23. If theports are numbered in rotational sequence, 23A, B, C, D, passage 28Abridges 23A and 23B while passage 22B bridges 23C and 23D. Upon aquarter-turn rotation of gland 22, the passages are moved in arotational direction relative to ports 23 and thereafter bridge ports23B and 23C in one pair and also bridging ports 23D and 23A in anotherpair. The next quarter-turn rotation of gland 22 and its passagestherein next bridges ports 23A and 23B by means of passage 22B andbridges ports 23C and 23D by means of passage 22A. In this manner, eachsuccessive quarter turn of gland 22 bridges pairs of ports not bridgedthe previous quarter turn cycle, alternating the pairs of :portsconnected together each operation of the solenoid 29.

Gland 22 is made of Teflon, which conforms to the face of valve seat 23under the pressure exerted upon it by rubber disc 20. The rubber disc 20acts like a fluid in transmitting pressure from washer 18 to gland 22and thereby tends to uniformly deform gland 22 in the direction of thevalve seat 23 face. In this manner, the Teflon surface against the valveseat 23 face is sealalbly conformed thereto over the entire contactingsurface. Any wear or deformity otherwise tending to contribute to amisfit and loss of seal between gland 22 and valve seat 23 iscompensated by the distributed pressure against gland 22 deforming it toa complete seal throughout each point of contact with seat 23.

Valve body is held to the solenoid body 34 by means of retaining ring 35and coupling ring 36. The plunger 29 is actuated by solenoid coil 37,having leads 38A and 38B thereto, leading from the base aperture 39 ofsolenoid body 'base 34A. Plunger 29 runs in collar 40 and solenoidsubassembly 41, which are mated together by exterior threads thereon atthe interior of solenoid body 34. Rubber gasket 42 prevents vibrationalunthreading of subassembly 41.

The assembly consisting of solenoid body 34, solenoid body base 34A,coil 37, and gasket 42 may be threaded into suitable mating threads inan explosion-proof housing (not shown) so that leads 38 emerge insidesaid housing. Said assembly then serves as an explosion-proof seal,enclosing the solenoid coil 37 and leads 38 within said explosion-proofhousing, while the remainder of the valve may be exposed to combustibleatmospheres without danger of causing ignition of said atmosphere. Thevalve body assembly including the components located within valve body10 and caps 24 may be removed from the solenoid body 34 by means ofunfastening coupling ring 36. This removal allows plunger 29 to bewithdrawn. In this removed condition, the solenoid body assembly isretained in explosion-tight seal with said explosion-proof housing,permitting valve maintenance without the delay caused by observingsafety regulations pertaining to the opening of said explosion-proofhousing.

By uncoupling caps 24 and removing valve seats 23, said removal of thevalve body assembly may be accomplished without uncoupling the tubingconnection (not shown) attached to passages 25. This procedure allowsinspection or replacement of said lvalve body assembly or parts thereinwithout the use of tools.

While there has been shown what is considered to be a preferredembodiment of the invention, it will be manifest that many changes andmodifications may be made therein without departing from the essentialspirit of the invention. It is intended, therefore, in the annexedclaims, to cover all such changes and modifications as fall within thetrue scope of the invention.

What is claimed is:

1. A rotary switching valve comprising:

a stationary member having a working face with passages extendingtherethrough and terminating at the surface of said working face,

a rotatable member having a complementary face adapted to sealably abutagainst said working face and having at least one channel thereinbridging selected portions of said complementary face so that relativerotation of said complementary face to said working face in the plane ofthe abutting faces periodically form a bridging connection of a pair ofsaid passages by a said channel,

a resilient body bearing against said rotatable member at portionsthereof opposed to said complementary face,

pressure means consisting of a compression spring urging said resilientbody against said rotatable member thereby obtaining a uniform sealbetween said abutting faces,

holding means being a cylindrical member enclosing said rotatable memberand said resilient body and said spring for axially aligning saidresilient body and said rotatable member,

means for keying said rotatable member to said holding means in angularalignment so that rotation of said holding means results in rotation ofsaid resilient body and said rotatable member, and

actuation means for periodically rotating by a predetermined amount saidholding means thereby causing said rotatable member to turn itscomplementary face relative to said working face of said stationarymember.

2. The rotary switching valve of claim- 1 wherein said rotatable memberconsists essentially of a fluorocarbon resin and said resilient body iscomprised essentially of an elastomer.

3. The rotary switching valve of claim 1 wherein a first end of saidspring urges a first resilient body against its respective firstrotatable member and the opposite end of said spring urges a secondresilient body against its respective second rotatable member withkeying of said first and second rotatable members to said cylindricalmember for rotation therewith, whereby said spring is held compressedwithin said cylindrical member between said first and second resilientbodies.

4. The rotary switching valve of claim 1 wherein said holding means is acylindrical member having a set of catches axially aligned therewithabout the circumference of said cylinder, and

wherein said acutating means includes a solenoid operated hook havingits lip adapted to engage each of said catches in turn said hook beingflexibly mounted to the solenoid body so that said lip may flexibly rideover and engage one said catch upon solenoid de-activation and said lipmay pull said catch thus turning said cylinder a predetermined amountupon solenoid activation whereby said passages and said channels arepositioned in predetermined relationships.

5. A rotary switching valve comprising:

a valve body rigidly mounted to a valve mount having a substantiallyplanar working face with passages extending through said valve body andterminating at the surface of said working face,

a rotatable valve gland consisting essentially of a fluorocarbon resinhaving a substantially planar complementary face adapted to sealablyabut against said working face and having at least one channel thereinbridging a portion of said complementary face so that relative rotationof said complementary face to said working face in the plane of theabutting faces periodically forms a bridging connection of a pair ofsaid passages by a said channel,

a resilient body consisting essentially of an elastomer bearing againstsaid rotatable valve gland over a surface opposite said complementaryface thereof,

pressure-transmitting means for urging said resilient member againstsaid rotatable valve gland so that pressure is uniformly distributedover said surface opposite said complementary face of said valve gland,

a member having opposed convex ends one end contacting the center ofsaid pressure-transmitting means,

a helical spring having one end cupping the other convex end of saidmember thereby urging said member against said pressure-transmittingmeans,

a hollow cyl nder rotatably mounted to said valve mount for holding saidvalve gland and said resilient body and said pressure-transmitting meansand said member and said spring in series axial alignment within saidcylinder,

and keying means angularly aligning said valve gland with said cylinderwhereby rotation of said cylinder results in rotation of saidcomplementary face of said valve gland relative to said working face'ofsaid valve body.

6. The rotary switching valve of claim 5- wherein said valve glandconsists essentially of a fluorocarbon resin and said resilient bodyconsists essentially of an elastomer.

7. The rotary switching valve of claim 5 wherein said valve glandconsists partly of a fluorocarbon resin and partly a filler therefor.

8. The rotary switching valve of claim 5 with actuation means forperiodically rotating said cylinder at predetermined amount including asolenoid operator having a hook extension adapted to engage in turn eachof a set of protuberances disposed about said cylinder said hook beingflexibly mounted to the solenoid operator so that it flexes over a saidprotuberance upon solenoid de-activation thereby being in an engagingposition for pulling a said protuberance a predetermined amount uponsolenoid activation, said protuberance being disposed to result inselective angular registration of said abutting faces.

9. A rotary switching valve comprising:

valve mounting means,

a hollow cylinder rotatably attached to said mounting means,

a helical compression spring within said cylinder axially alignedtherewith and substantially centered therein,

generally spherical members within said cylinder located either end ofsaid helical spring each having a portion in cupped contact with a saidend,

pressure-transmitting discs having a diameter slightly smaller than thebore of said cylinder each having a centered indentation respectivelycontacting and cupping said spherical members at portions thereof opposite said portions cupped by said spring,

elastomer discs within said cylinder having a diameter slightly smallerthan said cylinder bore respectively contacting saidpressure-transmitting discs at surfaces thereof opposite surfacescontacting said spherical members,

substantially round and disk-shaped valve glands within said cylinderhaving a diameter slightly smaller than said cylinder bore respectivelycontacting said elastomer discs at surfaces thereof opposite surfacescontacting said pressure-transmitting discs and having planar facesdisposed opposite said elastomer discs,

valve bodies each having a planar working face contacting said planarfaces of valve glands fixed to said valve mounting means so that saidspring is held in compression by said valve glands and said elastomerdiscs and said pressure-transmitting discs and said spherical members inseries and the face of each said valve gland sealably abuts the face ofa respective valve body, and

keying means to align said valve glands angularly with said cylinder sothat rotation of said cylinder causes rotation of said planar faces ofsaid valve glands against said planar working faces of said valvebodies.

10. The rotary switching valve of claim 9 with actuation means forperiodically rotating said cylinder a predetermined amount including asolenoid operatotr having a hook extension adapted to engage each of aset of protuberances disposed about said cylinder said hook beingflexibly mounted to the solenoid operator so that it flexes over a saidprotuberance upon solenoid de-activation thereby being in an engagingposition for pulling a said protuberance a predetermined amount uponsolenoid activation,

said protuberances being disposed to result in selective angularregistration of said abutting faces.

References Cited UNITED STATES PATENTS 802,948 10/ 1905 Waterman251--230 X 2,233,192 2/1941 Armington 137625.46 X 3,131,706 5/1964Harban 137-62546 X 3,203,249 8/1965 Jentzsch 251 X 3,223,123 12/1965Young 137625.46 3,286,730 11/1966 Beck 137-625.21

ALAN COI-IAN, Primary Examiner.

1. A ROTARY SWITCHING VALVE COMPRISING: A STATIONARY MEMBER HAVING AWORKING FACE WITH PASSAGES EXTENDING THERETHROUGH AND TERMINATING AT THESURFACE OF SAID WORKING FACE, A ROTATABLE MEMBER HAVING A COMPLEMENTARYFACE ADAPTED TO SEALABLY ABUT AGAINST SAID WORKING FACE AND HAVING ATLEAST ONE CHANNEL THEREIN BRIDGING SELECTED PORTIONS OF SAIDCOMPLEMENTARY FACE SO THAT RELATIVE ROTATION OF SAID COMPLEMENTARY FACETO SAID WORKING FACE IN THE PLANE OF THE ABUTTING FACES PERIODICALLYFORM A BRIDGING CONNECTION OF A PAIR OF SAID PASSAGES BY A SAID CHANNEL,A RESILIENT BODY BEARING AGAINST SAID ROTATABLE MEMBER AT PORTIONSTHEREOF OPPOSED TO SAID COMPLEMENTARY FACE, PRESSURE MEANS CONSISTING OFA COMPRESSION SPRING URGING SAID RESILIENT BODY AGAINST SAID ROTATABLEMEMBER THEREBY OBTAINING A UNIFORM SEAL BETWEEN SAID ABUTTING FACE,HOLDING MEANS BEING A CYLINDRICAL MEMBER ENCLOSING SAID ROTATABLE MEMBERAND SAID RESILIENT BODY AND SAID SPRING FOR AXIALLY ALIGNING SAIDRESILIENT BODY AND SAID ROTATABLE MEMBER, MEANS FOR KEYING SAIDROTATABLE MEMBER TO SAID HOLDING MEANS IN ANGULAR ALIGNMENT SO THATROTATION OF SAID HOLDING MEANS RESULTS IN ROTATION OF SAID RESILIENTBODY AND SAID ROTATABLE MEMBER, AND ACTUATION MEANS FOR PERIODICALLYROTATING BY A PREDETERMINED AMOUNT SAID HOLDING MEANS THEREBY CAUSINGSAID ROTATABLE MEMBER TO TURN ITS COMPLEMENTARY FACE RELATIVE TO SAIDWORKING FACE OF SAID STATIONARY MEMBER.